Impact of human activities on benthic biotopes and species

Executive Summary 1. The Marine Life Information Network (MarLIN) has been developed since 1998. Defra funding has supported a core part of its work, the Biology and Sensitivity Key Information Sub-programme. This report relates to Biology and Sensitivity work for the period 2001-2004. 2. MarLIN Biology and Sensitivity research takes information on the biology of species to identify the likely effects of changing environmental conditions linked to human activities on those species. In turn, species that are key functional, key structural, dominant, or characteristic in a biotope (the habitat and its associated species) are used to identify biotope sensitivity. Results are displayed over the World Wide Web and can be accessed via a range of search tools that make the information of relevance to environmental management. 3. The first Defra contract enabled the development of criteria and methods of research, database storage methods and the research of a wide range of species. A contract from English Nature and Scottish Natural Heritage enabled biotopes relevant to marine SACs to be researched. 4. Defra funding in 2001-2004 has especially enabled recent developments to be targeted for research. Those developments included the identification of threatened and declining species by the OSPAR Biodiversity Committee, the development of a new approach to defining sensitivity (part of the Review of Marine Nature Conservation), and the opportunity to use Geographical Information Systems (GIS) more effectively to link survey data to MarLIN assessments of sensitivity. 5. The MarLIN database has been developed to provide a resource to 'pick-and-mix' information depending on the questions being asked. Using GIS, survey data that provides locations for species and biotopes has been linked to information researched by MarLIN to map the likely sensitivity of an area to a specified factor. Projects undertaken for the Irish Sea pilot (marine landscapes), in collaboration with CEFAS (fishing impacts) and with the Countryside Council for Wales (oil spill response) have demonstrated the application of MarLIN information linked to survey data in answering, through maps, questions about likely impacts of human activities on seabed ecosystems. 6. GIS applications that use MarLIN sensitivity information give meaningful results when linked to localized and detailed survey information (lists of species and biotopes as point source or mapped extents). However, broad landscape units require further interpretation. 7. A new mapping tool (SEABED map) has been developed to display data on species distributions and survey data according to search terms that might be used by an environmental manager. 8. MarLIN outputs are best viewed on the Web site where the most up-to-date information from live databases is available. The MarLIN Web site receives about 1600 visits a day. 9. The MarLIN approach to assessing sensitivity and its application to environmental management were presented in papers at three international conferences during the current contract and a 'touchstone' paper is to be published in the peer-reviewed journal Hydrobiologia. The utility of MarLIN information for environmental managers, amongst other sorts of information, has been described in an article in Marine Pollution Bulletin. 10. MarLIN information is being used to inform the identification of potential indicator species for implementation of the Water Framework Directive including initiatives by ICES. 11. Non-Defra funding streams are supporting the updating of reviews and increasing the amount of peer review undertaken; both of which are important to the maintenance of the resource. However, whilst MarLIN information is sufficiently wide ranging to be used in an 'operational' way for marine environmental protection and management, new initiatives and the new biotopes classification have introduced additional species and biotopes that will need to be researched in the future. 12. By the end of the contract, the Biology and Sensitivity Key Information database contained full Key Information reviews on 152 priority species and 117 priority biotopes, together with basic information on 412 species; a total of 564 marine benthic species.

Ranking of length-class seasonal and regional effects on dietary compositions of the co-occurring Pagrus auratus (Sparidae) and Pseudocaranx georgianus (Carangidae)

Using an effective combination of multivariate testing and ordination analyses, this study compares the extents to which the diets of two co-occurring fish species (Pagrus auratus and Pseudocaranx georgianus) are related to body size (length class), season and region and the rank order importance of those effects. Thus, volumetric dietary compositions were determined for these species on the lower west coast of Australia, where both are abundant, and for P. auratus from the mid west coast and P. georgianus from the south coast. The diet of P. auratus on the lower west coast was strongly related to body size and slightly less to season. With increasing body size, its diet shifted from predominantly ophiuroids to larger prey, such as brachyuran crabs, teleosts, echinoids and ultimately asteroids, probably reflecting a shift from foraging over soft sediments to areas over and around reefs. Seasonal changes on the lower west coast were restricted mainly to small P. auratus, while larger fish underwent seasonal changes further north. Analyses using a common size range of medium to larger P. auratus demonstrated that dietary composition differed more between regions than seasons. The relationships between diet and length class of P. georgianus on both the lower west and south coasts were less pronounced than for P. auratus and seasonal changes were restricted to the south coast, where amphipod consumption increased markedly in summer. The diet of P. georgianus was related far more to region than length class and season, with more small teleosts, small crabs, carideans and littorinids and less amphipods, isopods and small bivalves being ingested on the lower west than south coasts. Although crabs and teleosts were important typifying prey of P. auratus and P. georgianus, when co-occurring, the former predator tended to ingest greater volumes of larger and often less mobile prey. This reflects differences in dentition, jaw morphology and feeding behaviour and reduces the potential for competition for food resources. The results imply that P. auratus and P. georgianus are opportunistic feeders and that the effects of length class, season and region on dietary composition and their rank orders can vary markedly between species and for length class and season between regions for the same species.

US NOAA Fisheries and UK SAHFOS CPR surveys: comparison of methods and data

The US National Oceanic and Atmospheric Administration (NOAA) Fisheries Continuous Plankton Recorder (CPR) Survey has sampled four routes: Boston–Nova Scotia (1961–present), New York toward Bermuda (1976–present), Narragansett Bay–Mount Hope Bay–Rhode Island Sound (1998–present) and eastward of Chesapeake Bay (1974–1980). NOAA involvement began in 1974 when it assumed responsibility for the existing Boston–Nova Scotia route from what is now the UK's Sir Alister Hardy Foundation for Ocean Science (SAHFOS). Training, equipment and computer software were provided by SAHFOS to ensure continuity for this and standard protocols for any new routes. Data for the first 14 years of this route were provided to NOAA by SAHFOS. Comparison of collection methods; sample processing; and sample identification, staging and counting techniques revealed near-consistency between NOAA and SAHFOS. One departure involved phytoplankton counting standards. This has since been addressed and the data corrected. Within- and between-survey taxonomic and life-stage names and their consistency through time were, and continue to be, an issue. For this, a cross-reference table has been generated that contains the SAHFOS taxonomic code, NOAA taxonomic code, NOAA life-stage code, National Oceanographic Data Center (NODC) taxonomic code, Integrated Taxonomic Information System (ITIS) serial number and authority and consistent use/route. This table is available for review/use by other CPR surveys. Details of the NOAA and SAHFOS comparison and analytical techniques unique to NOAA are presented.